Antiemetics (anti-sickness medicines)
Antiemetics are medicines that prevent or reduce nausea and vomiting. They work in different ways, and the right one depends on the cause. Ondansetron, a 5-HT3 blocker, is used mainly for sickness caused by cancer treatment and surgery. Most are prescription medicines and should be used on a doctor's advice.
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How do Antiemetics (anti-sickness medicines) work?
Different antiemetics block different chemical signals that tell the brain to trigger vomiting. The 5-HT3 blockers, such as ondansetron, block serotonin receptors on nerves in the gut and in the part of the brain that controls vomiting.
Active ingredients of this type
These active ingredients belong to Antiemetics (anti-sickness medicines). They are listed A to Z.
- Ondansetron: Ondansetron is a prescription medicine that prevents nausea and vomiting caused by cancer treatment (chemotherapy and radiotherapy) and by surgery.
Common questions
Do all anti-sickness medicines work the same way?
No. Some block serotonin signals, some block dopamine, and some are antihistamines. The best choice depends on the cause of the sickness, so a doctor or pharmacist should advise. Do not combine them without asking.
When should vomiting be checked by a doctor?
See a doctor for vomiting that lasts more than a day or two, blood in the vomit, severe stomach pain, signs of dehydration, or vomiting in babies and young children. An anti-sickness medicine can hide a problem that needs treatment.
Can anti-sickness medicines affect the heart?
Some can. Ondansetron can affect the heart's rhythm, mainly in people with a heart rhythm problem, low potassium or magnesium, or those taking other medicines with the same effect. Tell your doctor about heart problems and all medicines you take.
Sources
- Ondansetron. MedlinePlus, US National Library of Medicine
- Ondansetron tablets: prescribing information. DailyMed, US National Library of Medicine
- ATC/DDD Index: A04AA01 ondansetron. WHO Collaborating Centre for Drug Statistics Methodology
- Diarrhoea and vomiting. NHS (UK)